The Marble node is a procedural texture that can be used to create marble-like noise. It is similar to a turbulence texture but more fine-tuned to create marble-like patterns.
In the following illustration (figure 1), the Marble and Gradient nodes are connected to the Diffuse channel. The Gradient node is used because the Marble node has no color definition by default. A Transform node is connected to Marble's Transform slot to adjust the PSR values.
Figure 1: A typical setup in the Node Editor using the Marble Texture node.
Power
A multiplier which controls the overall brightness of the texture.
Offset
Sets the position of the texture in 3D space.
Omega
Controls the detail in the underlying fractal pattern.
Variance
Randomizes the marble pattern.
UVW Transform
Sets the position, scale, and rotation of the texture on the surface.
Projection
Sets the way the texture is project onto the surface.